1. Field of the Invention
The present invention relates to an instrument for use in endoscopic ligation of varices, thereby blocking mechanical blood circulation to the varices to diminish or vanish or thrombose the ligated varices as one of therapies for gastric and esophageal varices due to hepatic diseases. The present invention provides a very simple instrument for safe endoscopic ligation of varices without fail.
2. Related Prior Art
Gastric and esophageal varices due to hepatic cirrhosis, etc. have been treated mainly according to an endoscopic sclerotherapy by injecting a sclerosing agent having an adverse effect on endothelial cells into varices or into vicinities of varices, thereby making the agent to stay locally at the injected sites and forming thrombi to block blood circulation thereto and decay the varices. However, the intravenous administration of the sclerosing agent having the side effect on the living body has caused complicated blood circulation behaviors such as portal hypertension and also various complications such as pulmonary thrombosis, pulmonary failure, renal failure, etc. Thus, one dose of the sclerosing agent is limited and also the treatment must be carried out in view of recovery of patients, resulting in prolonged treatment.
Recently, esophageal varix ligation has been used as a therapy for gastric and esophageal varices. As shown in FIG. 4, the esophageal varix ligation is a technique of sucking a varix 16 into a cylindrical device 13 mounted on the forward end of an endoscope 6, releasing an expanded elastic O ring 4 mounted in advance on the outer periphery of the protruded outer periphery of a cylinder 14 inserted into the device 13 from the outer periphery by pulling back the cylinder 14 with a wire inserted through a forceps channel in the endoscope 6, thereby fixing the O-ring around the basis of sucked polyp-like varix and mechanically ligating and decaying the varix by the contracting force of the expanded O-ring 4. The forward end of the cylinder 14 is protruded from the forward end of the device 13.
Ligating kit now in use for this purpose will be explained in detail-below, referring to FIG. 3.
FIG. 3 schematically shows the structure of a ligating kit now in practical use.
A cylinder 14 provided with an expanded elastic O ring 4 on the outer periphery at the forward end is inserted into a cylindrical device 13 fixed to the forward end of an endoscope 6, while the forward end of the cylinder 14 provided with the expanded O ring 4 on the outer periphery is protruded from the forward end of the cylindrical device 13. A wire 15 is connected to the cylinder 14 through the forceps channel 9 in the endoscope 6, and the cylinder 14 can be pulled back by pulling the wire 15, whereby the expanded O ring 4 is released from the forward end of the cylinder 14.
Increased use of esophageal varix ligation will be expected because no sclerosing agent is used at all or the dose of sclerosing agent can be reduced, even if the sclerotherapy is applied together at the same time, with the result that complications can be reduced and a burden on patients can be lessened or number or duration of treatment can be reduced. However, in the case of sucking a varix 16 into the device 13, vertical access of the device 13 to a varix 16 to surround it is preferable, because inclined access often give rise to a gap in the surrounding of varix, resulting in insufficient suction and failure to ligate the varix.
Furthermore, the kit for use in the esophageal varix ligation has various problems. For example, the endoscopic sight is narrowed because the device 13 is fixed to the forward end of the endoscope 6. In the case of ligation of gastric varices on the convexity of stomach, the endoscope must be turned for the ligation, and when there is bleeding from the varices, the blood often accumulates in the device 13, losing the endoscopic sight. Wire 15 for releasing the expanded O ring 4 is extended to the forward end of the endoscope through the forceps channel 9 in the endoscope 6, and thus washing of stomach and esophagus or aspiration of washing solution therefrom through the forceps channel cannot be carried. It would be possible to use an endoscope with two forceps channels, but most of hospitals are equipped with endoscopes only with one channel and not with two channels and thus cannot promptly meet such requirements.
Furthermore, when the endoscope is turned, the wire 15 fails to smoothly slide through the forceps channel 9 due to the friction, and sometime the expanded O ring fails to be released even by pulling back the wire 15. Particularly for ligating varices on the convexity of stomach it is inevitable to turn the endoscope, but in the actual practice the device 13 is given inclined access to a varix to ligate it without turning or with least turning of the endoscope 6.